I believe the 356 is older and it supports the older 3Gb/s SAS shelves according to HWU. It may have the 3.5" enclosure too or an adapter for it I'm not sure. But the 356 is listed to support the 3Gb shelves but the 357 is not. Probably exact same SSD otherwise.
If you're ordering a new one, 357 would probably be what you need.